Compass Pathways Releases Promising New Data from Landmark Psilocybin Therapy Trial

New data released by Compass Pathways about its proprietary psilocybin therapy COMP360 has revealed there is no evidence to suggest that it causes severe adverse events and that the treatment could offer benefits beyond reducing a patient’s depressive symptoms.

These findings add to topline data released last month by the company from its Phase 2b clinical trial evaluating COMP360 for treatment-resistant depression. The trial, which was the largest psilocybin therapy trial conducted to date, compared two active doses of COMP360 — 25mg and 10mg — with a 1mg dose.

The initial results from this trial were promising, showing that patients who were administered a 25mg dose experienced a reduction in depressive symptoms after three weeks, with 24.1% of patients sustaining this response at the 12-week mark. But these results were also met with some disappointment because the majority of participants in the study experienced treatment-emergent adverse events (TEAEs). While 90% of these were mild to moderate effects, about a dozen patients experienced severe TEAEs.

Further analysis of the trial data has provided more insights into the safety of the treatment. “Further understanding of the timing and circumstance of adverse events in the trial demonstrates that COMP360 psilocybin therapy was generally well-tolerated,” explained Compass Pathways’ Chief Medical Officer Dr. Guy Goodwin.  

“More detailed analysis of the safety data supports our conclusion that there is no evidence to date to suggest a causal relationship between the serious adverse events of suicidal ideation, suicidal behavior and self-injury, and administration of COMP360 psilocybin therapy. Unfortunately, these events occur unpredictably and are to be expected in this patient population.”

The new results released today also showed that patients who received a 25mg dose of the therapy experienced a more significant improvement in measures of anxiety, positive and negative affect, quality of life, daily functioning, cognition, and self-reported depression three weeks after the treatment than those who received a 1mg dose. 

“Many of the participants in this study had suffered for years with severe and crippling depressive disorders despite multiple treatment trials with traditional antidepressant medications and therapies,” said the trial’s Principal Investigator, Dr. Sidney Zisook. “To see so many experience a robust and sometimes persisting response — and a new, brighter, more positive attitude — during the course of the study was immensely gratifying and hopeful.”

Further analysis of the trial data is ongoing, and Compass Pathways says it plans to submit the complete data from the trial for publication next year. This research aimed to find the appropriate dose for a larger, Phase 3 trial, which the company anticipates will begin in 2022.

“We believe this [treatment] could make a tremendous difference to patients suffering with treatment-resistant depression, who have few options available to them,” Dr. Goodwin said. “Remember, a quarter of the 25mg group maintained response, as measured by the Montgomery–Åsberg Depression Rating Scale (MADRS) at 12 weeks after a single administration with no other antidepressant medication. This finding in itself is unprecedented.”